The present invention relates to a method for producing a connection electrode for two semiconductor zones which are arranged one above another and are doped complementarily with respect to one another, in particular a connection electrode for a source zone and a body zone of a power MOSFET.
In order to avoid negative effects of a parasitic bipolar transistor formed by the sequence of the drain or drift zone, the body zone and the source zone in the case of a power MOSFET, it is known in the case of power MOSFETs to short-circuit the body zone and the source zone. For this purpose, a source electrode connected to the source zone is realized in such a way that it also makes contact with the body zone and thereby short-circuits the source zone and the body zone.
In the case of so-called trench MOSFETs, in which the body zone and the source zone are arranged in a manner lying one above another in a semiconductor body and in which gate electrodes are arranged in trenches extending through the source zone and the body zone, it is known to arrange such a connection electrode in a trench extending into the semiconductor region (mesa region) between two gate trenches through the source zone right into the body zone.